<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!-- {}表示对象  []表示数组-->
<div id="app">
    hello
    {{message}}
</div>

<script src="http://cdn.jsdelivr.net/npm/vue@2.5.21/dist/vue.min.js"></script>
<script>
    var vm=new Vue({
    el:"#app",
    data:{
    message: "hello!"
    }
    });
</script>

</body>
</html>